1. Field of the Invention
The present invention relates to an adjustable eyeglasses cord structure, more particularly to an adjustable eyeglasses cord structure enabling adjustment of the cord angle, in which the adjustment is achieved by a ball valve shape member.
2. Brief Description of Prior Arts
Generally, eyeglasses has been becoming an indispensable item in our daily live. Besides vision correction, eyeglasses also plays the roles of sun shading, aesthetic and eyes protection. However, wearing eyeglasses for a long time often suffers some inconvenience. For example, there might be the cases of falling-off of the eyeglasses in walking, working, or exercising; or of damaging by press or collision when eyeglasses are taken off. Thus, relevant industries have proposed to provide an eyeglasses cord which is to be provided between the temples for hanging on the neck. In this way, even the eyeglasses is carelessly detached from wearing in working, walking or exercising, it can be prevented from dropping down to ground effectively by the eyeglasses cord which is tied to the temples and hung on user's neck. When a user wants to take off the eyeglasses and to take a recess for his eyes, the eyeglasses is hung on user's neck by the cord, and user need not to worry the case of damage due to carelessly dropping down to ground or pressing due to improperly located.
Conventional eyeglasses cord structure usually has flexible fitting portions provided on both ends, each flexible fitting portion being provided with a metal ring body which is provided for preventing the temples from coming off the fitting portion. In implementation, the temple is simply fitted into a hole in each flexible fitting portion to accomplish the setting, and the eyeglasses cord is then hung on user's neck.
Referring to a Taiwanese Patent Pub. No. M385707 entitled “Improvement on Eyeglasses Cord Structure”, which is mainly formed by an eyeglasses and a hanging cord. A hanging hole is provided on the front segment of each temple. The hanging cord has locating members provided on both ends thereof, one end of each locating member has a fitting portion to be integrally combined with the hanging cord and the other end is provided with a clamping portion with elastic force. The clamping portions of the locating members are combined with the hanging holes on the temples so that users can hang the eyeglasses on their neck conveniently.
The abovementioned eyeglasses cords can facilitate wearing of eyeglasses for users, but there are yet rooms for further improvement.    1. The eyeglasses cord is ordinarily a flexible cord, it is unable to adjust the cord angle according to user's need.    2. The metal ring body of the fitting portion can render damage to the temples of eyeglasses, making the temples scratching or destroying the hanging holes of the temples first.    3. Assembly and disassembly are inconvenient.
Further, an U.S. Pat. No. 7,467,867 B1 is disclosed as shown in FIG. 6, which is a retention tube (6) having a through hole (61) thereon. One end of the through hole (61) is an aperture the diameter of which is able to pass over the temple (7), and the other end of the through hole (61) is an opening the diameter of which is able to pass over the steel cord (8). The through hole (61) has a bead (62) provided therein and the bead (62) has a through aperture (621) for the passing over of the steel cord (8). The end of the steel cord (8) is locked by a metal retainer (81) so that the steel cord (8) does not come off the through aperture (621). This structure has the following disadvantages found in its implementation.    1. As the through hole of the retention tube corresponding to the end of the steel cord is shrunk to a diameter equivalent to that of the steel cord, just like to overlay the steel cord, the steel cord is only used with a single angle after fitted with the temple, so that the steel cord is unable to be adjusted to a suitable cord angle different for each individual.    2. The steel cord has stiffness, so the steel cord will displace forward when it is in using, and this will cause scratch of temple by the metal retainer.
In view of the above reasons, the inventor of the present invention hereby proposes an adjustable eyeglasses cord structure according to his long-term abundant experience in development and manufacturing activities in relevant fields, and based on the effort conducted on the conventional structure with constantly improving principle, so as to achieve better implementation value.